Fishes in my aquarium died one by one since last week. I lost around 10 fishes in 7 days! I’m very sad about this. I’m not sure what happen, i’ve checked the dead body of the fish and it shows not symthoms of fighting. I’ve tried to change part of my tank water, put medicine, etc etc. What i didn’t shows any luck.

Two days ago, when i reach home after work, I saw my snow cichlid not swimming around (normally cichlid are the most active one in my tank) and it seems like having some problem. After few minutes of look at it, it died in front of me just like tat. I really feel sad about this. Since i cant find out what’s going wrong, the best solution for me is to change the water again. So on that day itself, i decided to clean up my whole tank, my external canister filter and change 90% of the tank water.

Before the tank water change, some of the fishes seems not active
enough compare to before. Yesterday when i back home after work, they
seems swimming happily like old days. Glad to see that they are healthy again.

This morning while I’m feeding my fishes, all the fishes swimming happily except my white snow cichlid. it seems having some problem and not swimming actively like before. I really worried about this snow cichlid since i lost 2 chilid for the past 1 week. I do not wish to lose any fishes.